import { useIntersectionObserver } from '@vueuse/core'
export const lazyPlugin = {
    install(app) {
        app.directive('img-lazy',{
            mounted (el,binding) {
                // el:指令绑定的那个元素
               const { stop }  = useIntersectionObserver(
                    el,
                    ([{ isIntersecting }]) => {
                        if(isIntersecting) {
                            // 进入视口区域
                            el.src = binding.value
                            stop()
                        }
                    //   targetIsVisible.value = isIntersecting
                    },
                  )
            }
        })
    }
}